The development of low-polarization coatings for cardiac pacing, sensing and defibrillation electrodes is proposed. The coatings address the needs of the cardiac rhythm management industry in the development of high-impedance, low-polarization pacing electrodes, low impedance defibrillation electrodes, and post-stimulus sensing methodologies for rate adaptive pacing employing a single pacing and sensing electrode. The coatings are reduction-oxidation (redox) materials with tailored surface morphologies that maximize low-polarization charge injection in thin (<150 nm), physically and chemically robust coatings. Innovations in the chemistry and deposition of the redox coatings are proposed that will enhance in vivo chemical and physical stability. The coatings will accommodate organic overlayers, such as PEG and steroid eluting membranes, and allow chemical surface modification to improve biocompatibility and moderate fibrotic tissue encapsulation. In Phase I, the coatings would be applied to endocardial pacing and defibrillation electrodes. In vitro characterization would include polarization during pacing and defibrillation, impedance, stability in biomolecule containing physiologic media and stability under mechanical challenge. The relationship between composition and morphology of the coatings and their performance as pacing and defibrillation electrodes would be established. In Phase I, organic surface treatments would be introduced and testing to establish chronic in vivo and functionally stability undertaken. PROPOSED COMMERCIAL APPLICATION: A low-polarization coating for cardiac pacing, defibrillation and sensing electrodes has commercial potential in an extremely large market. Besides cardiac applications, the coatings will be suitable for deep-brain stimulation, cortical stimulation and recording in functional electrical stimulation for sensory and motor prostheses, and vagus nerve stimulation for epilepsy. These are growing markets in which the use of the coatings will have clear clinical benefit with significant commercial potential.